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New submitter lashicd sends news that the U.S. Naval Research Laboratory has announced a successful proof-of-concept demonstration of converting seawater to liquid hydrocarbon fuel. They used seawater to provide fuel for a small replica plan running a two-stroke internal combustion engine.
"Using an innovative and proprietary NRL electrolytic cation exchange module (E-CEM), both dissolved and bound CO2 are removed from seawater at 92 percent efficiency by re-equilibrating carbonate and bicarbonate to CO2 and simultaneously producing H2. The gases are then converted to liquid hydrocarbons by a metal catalyst in a reactor system. ... NRL has made significant advances in the development of a gas-to-liquids (GTL) synthesis process to convert CO2 and H2 from seawater to a fuel-like fraction of C9-C16 molecules. In the first patented step, an iron-based catalyst has been developed that can achieve CO2 conversion levels up to 60 percent and decrease unwanted methane production in favor of longer-chain unsaturated hydrocarbons (olefins). These value-added hydrocarbons from this process serve as building blocks for the production of industrial chemicals and designer fuels."

This only makes sense if you have a nuclear reactor or long transmission lines plugged into the grid somewhere and probably belching all kinds of toxic death.This is essentially making a complex liquid energy battery.

It's unlikely that this would obviate completely the need for external supplies of fuel. At best it would probably only marginally decrease the depletion rate of on board stocks allowing for a somewhat longer cruise before a resupply is needed. There are probably other downsides to using this system too. For example, there are parts, maintenance and possibly extra wear and tear on the reactor which now not only has to propel the ship but also power an energy intensive conversion process from seawater to jet

Aircraft carriers are like a space limited island villages with a nuclear power plant. The power goes to more than just propulsion so its built into the design plans. Desalination, waste water treatment, and machine shops for sure. There is probably a tiny factory on board for as many products as they can have one for. Manufacturing on demand is highly desirable. Not only is resupply is a massive pain, but it takes up valuable storage space.

There's no doubt that manufacturing fuel on board is desirable from a logistics standpoint. The question is cost, not just monetary but energy. As you're no doubt aware, hydrocarbon fuels are incredibly energy dense which means that an equal amount (and probably more) energy most go into their creation from scratch using the most basic raw materials, H2, CO2 and CO. The question is how much space is available onboard for production scale versions of these reactors and how much steam and electric power will the reactor have to supply to make this work. I don't know, but I would guess lots. This fuel production sounds like an energy hungry process. How much power and steam can be spared from other onboard needs to power fuel production? Would this stress the reactors, possibly reducing service life or requiring more frequent nuclear refuels? There are trade-offs here, it's not a slam dunk.

There's no doubt that manufacturing fuel on board is desirable from a logistics standpoint.

Is it, though? If you run out of fuel, just refuel the damn thing. At sea refueling is trivially easy, all you need is a ship that can carry a lot of fuel, a pump, and a hose. Pretty much any ship will work if it will carry enough- for example in the summer fishing season in Alaska, the canneries hire on the big Bering Sea crab boats to act as tenders, and they provide fuel to the smaller salmon boats. Refueling a destroyer at sea isn't all that different except in scale, and the Navy has logistics ships designed specifically to do this.

The other variable that needs to be considered is time. I'm guessing that not only is this process very energy-intensive, it takes a while. The article shows them fueling a hobby plane with the fuel they've generated, which suggests they're not exactly churning the stuff out by the barrel. Unless you can create a system that can deliver tens of thousands of gallons a day, it's probably going to be far faster to divert a support ship and have it show up with 7 million gallons of the stuff.

And realistically, when is a carrier or other ship likely to be far from supply lines? Current and potential flashpoints would include places like Syria, the Ukraine, Iraq, Iran, Afghanistan, Pakistan, Taiwan, and North Korea. Likely areas of operation for the Navy will be the Mediterranean, Arabian Sea, South China Sea, and the Sea of Japan. None are far from civilization. Not coincidentally, the U.S. already has bases near all of these places. The U.S. Navy did have a tough time in the Pacific theater in WWII, trying to fight the Japanese in Indonesia on the far side of the Pacific, and that was even after they had the good fortune that the Japanese didn't think to bomb the fuel tanks in Hawaii. Part of what they learned from Pearl Harbor is that you don't wait until the fighting starts to establish a supply chain and stockpile fuel.

Japan, like most of civilization, is not a fuel source, just a fuel depot. A foreign base is an advantage and a disadvantage, an overhead expense, a sore in foreign relations, and a vulnerability requiring additional defense.

As far as supply lines go, this is like taking off the pump-fed diving suit and breathing with gills.

Your point is well taken if this process is just an auxiliary. But if every vessel in an armada can refill from purpose-built reactor-powered saltwater-crackering seaworthy catalytic beds, then it's a much different force, one that can't be stopped at the Solomon Islands.

At sea refueling is trivially easy, all you need is a ship that can carry a lot of fuel, a pump, and a hose.

"Trivially easy"? I think the Navy would disagree strongly with you on that. There are a huge number of non-trivial logistics issues. You have the expense of maintaining a second ship. You have to have that ship transport the fuel to an arbitrary location on the globe. You have to keep the fuel supply safe and ensure that the fuel tender isn't tracked back to the ship it is refueling. You have a ship with a large amount of potentially explosive fuel on board with all the attendant safety hazards that causes. It means your ships are limited in where they can go and how long by their fuel supplies rather than mission parameters.

The fact that they're fairly good at doing it doesn't mean it is something they find easy or useful. Cut of a military's fuel supply and they are effectively helpless. Fuel logistics are a HUGE and expensive problem for the military. It supposedly costs something like $16 to transport $1 worth of fuel. Also bear in mind that a lot of fuel comes from pretty volatile locations that we are likely to engage in hostile action with. There is a reason our military is putting a LOT of money into alternative fuel research. It's a huge cost and a huge tactical/strategic problem for them.

And realistically, when is a carrier or other ship likely to be far from supply lines?

Middle of the Pacific perhaps? Or any other ocean? Or when near hostiles? You don't really want to be refueling anywhere close to the people you are fighting if you can avoid it.

IIRC, one of the reasons the final conquest of Germany didn't happen even faster than it did in WWII is that, towards the end, both the Western Allies and the Soviets kept outrunning their supply lines.

Fuel was certainly the critical factor in the final victory. The Germans had nothing but coal, which they used in very creative ways, but they depended on a couple of refineries they'd captured from Russia. In particular, there was a place called Pleisse (or something like that) which was destroyed in the spring of 1945. One high-ranking general later wrote in his memoir that he knew on that day that it was all over.

Even if carriers did not need fuel, they would still require food resupply, equipment resupply, spare parts resupply, munitions resupply, crew swaps, etc. so carriers and other ships would still need to meet with supply ships every other week even if you take fuel out of the equation.

At sea refueling trivially easy ?Yes, it's done often, and it works, but the important aspect isn't if it's a safe/common operation, but rather cost.It's fairly well documented that the cost to deliver jet fuel to a destroyer/cruiser/carrier in the middle of an Ocean is anything but cheap. "trivially easy" utterly disregards the cost of the task at hand, which is high.Just operating oilers to transport fuel is a high enough cost.In the long run, this technology could be perfected to cost less to produce jet

former navy machinist mate here - theres more available space than most people realize on a carrier. we were exceptionally good space management, so that wouldnt be an issue. the reactors wouldnt have an issue with producing enough energy - the whole powerplant is built with a ton of production headroom. we would often operate with up to 1/3 of our equipment either off or idling and still be well below the energy demands of the ship, even during flight ops in combat zones. there would be a slight reduction in how long the fuel would last, maybe 20 years instead of 25. but, to have onboard aviation fuel production would be very very worth it. stress to the reactors would be minimal, theyre designed to be operated at high capacity for extended amount of time and the navy doesnt come anywhere near running them at their actual capacity - everything is designed with a LOT of headroom! youre right that it isnt a slam dunk, but it is very doable

All current carriers also have two reactors. The first carrier the USS Enterprise had 8 reactors. The Ford's new reactors do make more power but the amount is not publicly available. We do know they make 3 times as much electrical power but that does not include the propulsion power.

The onboard nuke can cruise an aircraft carrier at 30+ knots. If this tech can fit inside a fuel bunker ship with a carrier nuke to power it, then you've got a bunker ship that never needs to return to port...

Thorium fuel is highly available, and the fuel is a natural neutron-absorber, so the natural state of the reactor should you need to SCRAM is to shut down the neutron chain reaction and push the molten salt fuel out of the reactor core, where it is cooled. And the fuel byproduct is only dangerously radioactive for a couple hundred years, and after that, it is safer to handle than Uranium ore. And it can't be weaponized.

So, do we have a requisite $40 billion to earmark to this program and get it up and runni

There has not been a working commercial plant, but there has been a working thorium reactor. Oak Ridge had one running for 15 thousand hours. But the folks running the AEC wanted plutonium, so they shut down thorium research in 1973. wikipedia [wikipedia.org] has more detail.

Yes, so long as you have sufficient energy available, you most certainly can do the "net effect" of making hydrocarbon combustion run backward. It simply takes MORE energy to do that than you got from the original hydrocarbon combustion, because of inevitable inefficiencies in the system. So, if you have the energy to waste, and have no easier supply of hydrocarbons available, this certainly is Cool. Just not very practical for everyday use, worldwide....

We have lots of options for producing electricity. We don't have very many for fuelling our cars. Hydrocarbons make a great portable energy store that we happen to already have a lot of infrastructure set up to use. Processes like these let you store energy in that portable, high density, already supported "liquid battery."

I was under the impression that electrolysis isn't a fast process but the article does mention some kind of patented "electrolytic cation exchange module", perhaps combined with some kind of "bicarbonate" reactant? In any case, it seems clear that they've found a way to substantially speed up H2 and CO2 production from seawater. From there it's not much of a stretch to produce CO and then hydrocarbon fuels, jet fuels in this case, via the well understood Fischer-Tropsch process or similar.

Water is hydrogen and oxygen. It can be very simple and you can do it yourself in about 10 minutes. Get two pieces of wire, strip the insulation off of it, connect one to the + terminal of a 9V transistor battery, the other to the - terminal. Pour a drinking glass full of water, put in about a TBSP of salt, stir it up. Then stick the wires, separately, into the glass so they don't touch. Bubbles will appear on each wire, the negative side is hydrogen and the positive side is oxygen.

Bubbles will appear on each wire, the negative side is hydrogen and the positive side is oxygen

Using NaCl as you describe to make the water conductive also results in the evolution of Cl - chlorine gas - more than oxygen. If your wires are bare copper, the metal also migrates from the positive wire to the negative wire, turning the solution nasty blue-green in the process.

Some caution is advised. Chlorine gas is toxic. It was used in shells to poison troops in WW1. Of course the amount is quite slight in the experiment.

Whereas both hydrogen and oxygen are perfectly safe and have never been known to case any sort of problem whatsoever... well, ok, there was the Hindenburg, and Apollo 1, and...

So if you do the described experiment while locked in a badly-ventilated room, leave it running for long enough to increase Ever Ready's share price by 1%, ignore the eye-watering stink that even a whiff of chlorine will produce and then light a cigarette, you could be in real trouble. If only from all the crap in the cigarette smoke...

However, all this pales into insignificance alongside the experiment's reckless use of the liquid death that is Dihydrogen Monoxide [dhmo.org]!

Seriously, guys, when everything is described as dangerous, nothing gets treated as dangerous. If you're not sure what it is, don't wait for someone on the internet to tell you not to snort it.

I met a guy that was right in the middle of a fairly big hydrogen explosion in a pyrometallurgy lab. He was fine and barely lost his eyebrows. Some distance away from the ignition source however the wave front built up enough energy to blow bricks out of the wall.

An amp of current produces about a half a litre per hour of hydrogen gas. A 9V batter with 0.5-1 Ahr is not going to produce less than a litre of hydrogen gas, which wouldn't be a problem even in a small closet.

A litre? OK, you get to stick the burning splint into the collection bottle to test that it's hydrogen. I'm quite attached to my eyebrows. A few ccs in a test tube is enough for a satisfying 'pop'.

Half a litre of pure O2 is more than enough to do something inadvisable with, too. Pass the wire wool and the blowtorch please...

However, I wasn't suggesting that the hydrogen and oxygen were more of a deadly peril than the chlorine - just that its silly to single out one chemical because its been used in warfar

It depends how small a ruler you use to measure it [wikipedia.org]. Using a ruler with the precision of a Planck length, Canada's coastline to would actually be measured at over a quadrillion (1x10^15) km long, which is over 100 light years (if space were infinitely divisible, theoretically smaller rulers yet would give ever larger amounts without ever approaching any particular limit at all). There doesn't seem to be any practical point to using arbitrarily small ruler to measure things like coastline, however, since

TFA was points to a 2012 press release, but it contains not much more information. They must need to supply energy to this reaction, but whether this energy is as heat, electricity or something else is unclear.

I see two uses from the point of view of the U.S. navy. One is to put one of these chemical plants in an aircraft carrier, power it with the carrier's reactor, and generate fuel for the aircraft on board. The other is to put the chemical plant on a nuclear powered supply ship, which will then transfer the fuel to non-nuclear surface ships.

From a world energy point of view, this is a way to turn non-fossil fuel power (nuclear, hydro, wind) into hydrocarbon fuel, with the overall process being carbon neutral. Burning fossil fuels to provide the energy for this process would certainly be counter productive in terms of CO2 emission and very likely economically counter productive as you'd be better chemically processing your fossil fuel instead.

By the time you're going to all of this trouble to turn electricity into fuel, it is unlikely that you'd want to run a car on it - you'd rather just have an electric car. For aircraft we really have no good alternative to hydrocarbon fuels, so it could be used here. However, on the road to a low-carbon future, we have decades worth of lower hanging fruit (notably coal power stations) before we really need to care about whether our aircraft fuels are carbon neutral.

Conspicuously missing from the articles is the energy efficiency of this process. Given the $3-$6 per gallon projected jet fuel cost, presumably the efficiency is not too bad. (I notice this number hasn't changed since 2012 which makes me suspicious that it is more guesswork than calculation.)

By the time you're going to all of this trouble to turn electricity into fuel, it is unlikely that you'd want to run a car on it - you'd rather just have an electric car.

Not sure about that. Electrical energy can't be stored easily -- you need some high-tech battery with all kinds of electrolytes and complicated chemicals, and still the capacity is relatively measly. Electricity works much better if it can be consumed right after it is produced, without storing it (but if this can be achieved, electricity is otherwise very flexible -- it can be scaled up and down easily, and it can be transported quickly over long distances). HC fuels OTOH work well for storing energy -- they already store it, you just have to pour them into any airtight vessel, and they'll stay there until you burn them. So electricity and HC fuels might compliment each other quite well if the right technologies are in place. Any process that can convert electricity into fuel (and also happens to consume and thus neutralize the byproduts of burning the fuel) should be almost like a gold mine, if it can be scaled up sufficiently. So if this water-to-fuel conversion or similar processes can be made to work efficiently, chances are liquid fuels will continue to be the preferred method for large-scale mobile energy consumption needs.

I always thought an electrolysis plant was the ideal power sink/storage system for those renewable energy sources like wind whose availability didn't always line up with grid demand. Another good use would be desalination plants.

I know the processes are "inefficient" but efficiency shouldn't matter much if the input energy is free. It seems more inefficient to build windmills you don't let generate electricity when the wind blows.

By the time you're going to all of this trouble to turn electricity into fuel, it is unlikely that you'd want to run a car on it - you'd rather just have an electric car.

Not sure about that. Electrical energy can't be stored easily -- you need some high-tech battery with all kinds of electrolytes and complicated chemicals, and still the capacity is relatively measly.

Most trips in cars are short. Once we can "refuel" on any streetcorner, batteries won't even seem like a hindrance any more. Contactless charging on highways will happen eventually as well. It's only really non-nuclear seacraft and heavier-than-air aircraft that are going to need to continue to burn liquid fuels for the foreseeable future.

This technology really has only valid military use, because it frees them from having to transport liquid fuels around the ocean; they only have to transport the nuclear f

One is to put one of these chemical plants in an aircraft carrier, power it with the carrier's reactor, and generate fuel for the aircraft on board.

the nuclear plant of an aircraft carrier doesn't have the power output required to produce enough fuel for the planes operating on the carrier. Most of the power produced by those reactors comes in the form of steam for the main turbines, only a relatively small part goes to the turbogenerators that supply electricity.

Plus there's the whole "shorten the life of the reactor cores by ~75% by running them at full power all the time to make jet fuel" thing....

It's got to still be cheaper than having to not only drag all that fuel around the oceans, but also having to have the ships to drag that fuel around, and the ships to protect those ships. Why are there so many comments in this story which completely ignore logistics? Fuel tenders don't just magic themselves to the location of your fleet.

It's got to still be cheaper than having to not only drag all that fuel around the oceans, but also having to have the ships to drag that fuel around, and the ships to protect those ships. Why are there so many comments in this story which completely ignore logistics? Fuel tenders don't just magic themselves to the location of your fleet.

I suspect I know more about the logistics then you do. Trust me on this, replacing reactor cores every five years, instead of every forty years, is not a trivial change in

Still not enough. I don't know what the Nimitz's electrical power generation is, but I DO know what the ratio of electrical power generation to heat generation of a nuclear submarine is.

If the two are even remotely comparable (no reason not to be, since the majority of the steam produced in a nuclear reactor aboard a ship is used to make the ship go, not to make the lights turn on), then even a Ford-class carrier can't make enough electricity to manufacture sufficient fuel onboard.

china's plan to convert coal to hydrogen to methane is about 50 percent energy efficient. For big commercial aircraft, it will be better to use liquid hydrogen directly.

The problem with this is that it's cryogenic with an extremely low boiling point of 20 K (Kelvin). You would have to carry a much heavier tank and insulation for the liquid hydrogen on the aircraft. There's also hydrogen leaks and transport of it to the airport from wherever it is produced.

You would also need to handle boil off of hydrogen while the plane is on the ground and the hazards of handling extreme cryo fluids, which is much more dangerous than handling jet fuel/kerosene. For example, oxygen condenses at 50 K meaning a poorly insulated tank (say due to damage inflicted while conducting maintenance) could be condensing liquid oxygen inside the plane's wing.

Further, there isn't a good reusable tank material for handling liquid hydrogen. Composites weaken over time due to gas pockets in the composite material (and thermal cycling) while metals such as aluminum are subject to hydrogen embrittlement.

I think there would be a huge redesign of aircraft in order to use liquid hydrogen directly. Thicker wings say from a flying wing design would be more fuel efficient.

There would probably also be huge logistics changes. Fuel tanks would probably have to be kept at extreme cryo temperatures indefinitely (including overnight) in order to prevent thermal cycling. You couldn't have the aircraft sit on the tarmac for hours because it would either lose too much fuel due to boil off or require considerable refrigeration power to keep boil off from happening. A traffic jam combined with a hot day and loss of grid power, would be a disaster for an airport.

Meanwhile methane can be converted to normal jet fuel with some additional loss of energy. For example, a coal burning plant/refinery on site of a coal mining operation could produce methane or longer chain hydrocarbons directly.

And at the current state of affairs, the cheapest hydrogen source is methane. Any plan for creating hydrogen from water is going to run into a similar degree of energy loss as that of converting coal and water to methane and syngas.

It depends upon what sort of fuel you're trying to produce. Methane can definitely be burned as a fuel, on your stove for example, but it's not a good aviation fuel. The idea here is to skip methane and go straight to ethane or propane which can be up-converted to even longer chain hydrocarbons via more heat and pressure, eventually yielding jet fuel. Artificial hydrocarbon fuels themselves are nothing new. The basic processes have been known since the early part of the 20th century, but because it's way cheaper to simply refine naturally occurring petroleum pumped out of the ground, nobody does synthetic hydrocarbons unless they have to. For example, Germany produced synthetic aviation gasoline from coal during WWII as supplies of oil were gradually cut off and South Africa produced diesel fuel from coal during the sanctions of the Apartheid era.

And on how difficult (read: expensive) it is to avoid unwanted byproducts. And on the possible market value of the byproducts.

If you can sell the liquid hydrocarbons that you want to produce and the methane that appears as a by-product for almost the same price, it would be economically counterproductive to spend money on reducing the fraction of unwanted methane. Just produce both and sell both.

In that case, you'd end up with a gaseous fraction that's mostly hydrogen, and a liquid fraction that's methane plus everything else.

I would assume you'd have to cool the mixture to a temperature between -161.49ÂC and -42ÂC (boiling point of the next heavier alkane, propane), so you get hydrogen and methane in the gaseous fraction, and propane and heavier alkanes in the liquid fraction.

What I'm wondering is, can they modify this process to produce edible hydrocarbons? Probably not something you'd enjoy eating, but the primary limitation on a nuclear submarine's endurance is the food supply for the crew.

What I'm wondering is, can they modify this process to produce edible hydrocarbons? Probably not something you'd enjoy eating, but the primary limitation on a nuclear submarine's endurance is the food supply for the crew.

While that is true, it really isn't an issue operationally. You can cram enough food onboard to last a long time, although towards the end powdered eggs get old. Given the space limitations inherent in a submarine it would make little sense to build in a food machine when the space could be better used to store real food.

This sort of reaction is nice, but don't forget that it needs gobs and gobs of energy to build those hydrocarbons. Don't forget that the energy you use up by burning that fuel (and some, because of the poor engine efficiency, reaction losses, etc.) had to be "put in" first. No free lunch here...

So yes, maybe a nuclear powered aircraft carrier could be producing jet fuel for its planes, but I don't see this supplanting the fossil fuels any time soon. It would be extremely expensive.

Converting electricity to liquid fuel, and in particular to a liquid fuel compatible with existing infrastructure, is potentially a big win. We're working on more sustainable electricity production, but no matter how much progress we make on the front there are still lots of applications where "throw some batteries at it" isn't a viable option for power storage -- being able to produce fuel from electricity and seawater is a way to bridge that gap in energy delivery without also requiring a breakthrough in electrical storage.

scale it up, and use it commercially means jets will stopping putting more CO2 into the air.Scale it up more, and Cars stop producing so much extra CO2.scale it up even more, it can be used as a carbon sink and buried.

This sort of reaction is nice, but don't forget that it needs gobs and gobs of energy to build those hydrocarbons. Don't forget that the energy you use up by burning that fuel (and some, because of the poor engine efficiency, reaction losses, etc.) had to be "put in" first. No free lunch here...

So yes, maybe a nuclear powered aircraft carrier could be producing jet fuel for its planes, but I don't see this supplanting the fossil fuels any time soon. It would be extremely expensive.

For uses where cost is a secondary consideration this technology would be useful. As for supplanting fossil fuels, this tech represents more of a price ceiling for fossil fuels because at some price pointy it becomes viable; just like any other fossil url sources that are expensive to extract from the ground.The real questions is how many kW are needed to produce fuels equivalent what can be refined from a barrel of crude oil. If say a 2gW nuclear plant could produce enough to be economically viable that wo

Not necessarily. There is talk of energy being 10,000x more abundant for humanity if we were to put development into the LFTR reactor. If we have cheap electricity via safe nuclear power, then using some of it to generate fuel from sea-water is surely a lot better than putting the effort into getting it out of the ground and then shipping it half-way around the world.

Then again, with cheap nuclear power, we can also effectively supply hydrogen (which is obviously much cleaner) for other internal combus

Maybe yes, maybe no. We're probably going to continue using liquid fuels for a long time. Some folks talk about the hydrogen economy being the replacement for hydrocarbons, but I've often wondered why. Hydrogen is a tricky fuel, starting from its relatively inefficient creation, through the difficulties in storage, transportation, distribution, to tricky bit of transferring and storing it in a vehicle tor provide sufficient usable range. I

Assuming that this process is 10% efficent let's take a look at the numbers.

Let's say you can dedicate half of the 1.1GWT (thermal) of the nimitz to aviation fuel production, if you're holding off coast.

And let's assume conservativley that the process is 20% efficent.

Diesel (pretty close to JP1) has an energy density of 35 MJ/L. This means at 20% efficency you'll be needing 175mj to create 1 liter of JP1.

At 1/2 1GWT you're looking at about 3 liters of fuel per second, or about 172,000 liters a day, or about 40,000 gallons. The nimitz has about 3 million gallons of fuel capacity so the refueling time of the entire tank from 0 would be around 2 months. According to this article here

http://large.stanford.edu/cour... [stanford.edu] (Also about marine jet fuel fabrication, provides some of the hard numbers) 3 million gallons is enough to refuel the onboard fleet about 20 times. So onboard fuel production would provide 1/3 of a full tank of gas for each aircraft onboard per day. Not terribly good, or bad.

What about the energy currently required to keep ships stocked up on aviation fuel, though?

Bingo. You mean the ships using some of that fuel, the staffing, the construction of fuel depots, the logistics chain of figuring out who gets the fuel, then the refuelers heading back empty to get more fuel to start all over again? The energy costs must be staggering.

Only in slashdot world would the brains that be, assume that the supply chain costs nothing.

When the supply chain is taken into account, that "made on board" fuel would have to be very expensive indeed before supply ship fuel would be chea

I don't think this would be viable on a submarine. They don't carry planes and space on submarines is typically hard to come by. Now it might be interesting to engineer a submarine purpose built to create fuel but that seems needlessly complicated when all the recipients of said fuel are surface vessels.

It's worth a thought experiment. A submarine fuel facility has the advantage of not being affected much by the surface seas. Perhaps it wouldn't go deep, but instead remain about 60 feet or so underwater. A float mechanism could be used to hoist the hoses to the surface, and then the hoses could be connected for fueling. This would keep the fueling platform itself stable and reduce the risks involved in a collision. It would probably require a significant re-engineering of the coupling mechanism, and I

Duke Nukem Forever stole the time schedule for nuclear fusion and tried to implement it in code. Unfortunately they were not able to successfully implement that schedule and so they ended up actually shipping the game.

It's just another data point that causes me to thing that our transition away from liquid fossil fuels is likely to be rather precipitous, faster than the transition away from leaded gasoline(which is barely within my memory).

All it takes is the first commercial project producing bio-fuel to start making money, then development work will drop the price of biofuel even as the cost of extracting fossil fuel will continue to rise.

You do realize that what they're producing here is artificial jet fuel, right? It's not "biofuel" because it isn't produced by bacteria or algae or other direct biological process. No, what they're talking about here is essentially the water gas shift reaction whereby dissolved CO2 in the seawater is combined with water vapor (aka steam) and carbon monoxide (produced via this "bicarbonate" reactant?) to yield carbon monoxide, carbon dioxide and hydrogen which more heat and pressure (steam) in the presence of an iron catalyst converts these products into short chain hydrocarbons (alkenes), probably ethanes (CH3) and propanes (CH4), and from there longer chain hydrocarbons with more heat and pressure until the desired blend is cooked up, jet fuels of CH9 to CH16. However, these processes don't really transition us away from fossil fuels or at least not into something besides a hydrocarbon fuel, whether produced artificially as in this case or refined from naturally occurring crude oil that we've pumped out of the ground.

If it was widespread and viable it means the fuel is coming out of the ocean rather from underground. So the carbon being released into the air would be the very sort of carbon that is being trapped in the oceans rather than stuff that's been locked underground for millions of years.

People in many parts of the world already pay the equivalent of US$7 for petrol, so the projected cost is quite viable for automobile use. However, it is likely that efficiencies of scale will bring down the price of seawater fuel if a mass production system is developed. If that is the case then this fuel could easily compete with conventional petrol at the pump.

NO! You cannot buy the sun.
Solar power != commercially available nuclear fusion
Moreover, just because Victorians could purchase steam turbines, doesn't mean nuclear fission was commercially available to them either.